Question

I am told not to keep my valve cap on when my tank is partially full, but worried about my o ring, what’s the reason?

Answer 1

After the cylinder has been used, many people leave the cap off to indicate that it has been used and it is not full. This eliminates anyone confusing it with a full cylinder

Answer 2

That's because when you put the tank cap on it means it's full of air and ready to go. The O-ring on the tank should be changed ever so often any wsy. It a pinch remember and O-ring has two sides and can be flipped..

Answer 3

leaving it off of a partially filled cylinder is a reminder that it need to be filled.

I have some tanks that I use to clean my pool and only use a small amount of air then. I leave the caps on them but check the gas supply when I gear up.